1. Field of the Invention
The present invention relates to a check valve for a fuel pump nozzle.
2. Description of the Prior Art
A common complaint among commuters and pleasure travelers alike is the tendency for gas station fuel pump nozzles to leak fuel after the nozzle has been removed from the fuel filler port of an automobile. Even with the addition of vapor trapping collars on the fuel nozzles which prevent fuel vapors from entering the surrounding air, the nozzles still drip fuel when the nozzle is removed. Consequently, several attempts have been made in the past to prevent pumps from dripping fuel after the flow of liquid has been stopped, but there has been little success, prior to the present invention.
U.S. Pat. No. 3,923,425 issued to David L. Porter et al. on Dec. 2, 1975, shows a fuel pump shut-off valve installed on an automobile. The fuel pump valve uses positive pressure across a diaphragm member to force an inlet/shut-off valve into a closed position.
U.S. Pat. No. 4,846,836 issued to Jonathan D. Reich on Jul. 11, 1989, shows a bi-directional valve which can be inserted into the gastroesophageal sphincter to provide a pressure differential artificial valve.
U.S. Pat. No. 5,377,729 issued to Alan J. Reep on Jan. 3, 1995, shows a spring-biased plug member mounted at the end of a fuel nozzle which prevents liquid such as gasoline from dripping or escaping out the dispensing end of the nozzle when liquid is not being dispensed through the nozzle.
British Patent No. 228,306 issued to Leslie Bernard Williams on Feb. 5, 1925, shows a fuel pump nozzle with a spring-biased, central poppet valve placed at the end of a fuel nozzle to prevent fuel from dripping after the main flow has stopped.
British Patent No. 1,027,271 to Cecil Duckworth et al. published on Apr. 27, 1966, shows a mechanically operated poppet valve centrally located within a fuel dispensing nozzle. Side protruding tabs are displaced by the throat of the fuel filler pipe during insertion of the fuel nozzle into the automobile to allow the central poppet valve to become unseated under fuel flow pressure allowing fuel to flow past the nozzle. When the fuel flow is terminated, the poppet valve reseats and seals the nozzle against drippage.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.